Method of uniting clad rods end-to-end and rendering joints uniform with the remainder of rods



June 12, 1951 2,556,160

J. G. AYERS METHOD OF UNITING CLAD RODS END-TO-END AND RENDERING JOINTS UNIFORM WITH THE REMAINDER 0F RODS Filed Feb. 21, 1947 INVENTOR. JOSEPH G. AYERS (QM/44 Wu; :5

Patented June 12, 1951 END AND RENDERI NG JOINTS UNIFORM WITH THE REMAINDER'OF RODS J Joseph G. Ayers, Mount Lebanon Township, AlleghenyCounty, Pa., assignor toCopperweld Steel Company, Glassport, Pa., a corporation of Pennsylvania Application February 21, 1947, Serial No. 730,170

4 Claims. (01. 29-15542) This invention relates to the drawing of wire in a continuous length from wire rods of limited length and, in particular, to the welding end-to-end of metal wire rods composed of a core and a layer of cladding metal thereon.

In drawing wirecomposed of a single metal, it is common to weld successive wire rods together end-to-end, in order to save the loss of time entailed in threading the wire rods through the dies individually, and to produce a continuous wire of greater length than can be drawn from a single red. Special difficulty is encountered, however, when it is attempted to apply this practice in the drawing of clad wire, e. g., wire composed of a core of steel having a cladding layer of copper welded thereon. The copper of the outer layer melts at a temperature considerably below the welding temperature of the steel core. The loss of copper from the surthe section of copper which may be restored without exceeding the outside diameter of the composite rod. In addition, copper inclusions in the weld impair the strength thereof so materially that the weld constitutes a perceptibly weak point in the finished wire. The strength of the weld is also reduced by the increase in the grain size of the metal resulting from the heating necessary for welding. All portions of the finished product, of course, must meet certain minimum speci- 'fications as to strength and conductivity, in order to be marketable as prime material.

I have invented a novel method for uniting composite wire rods such as copper-clad steel rods, whereby the aforementioned difficulties areovercome. In a preferred practice, I remove the cladding layer from the rods adjacent the ends to be butt welded. Specifically, I machine the rod ends on a taper to a minimum diameter at their extremities less than the original diame-'- ter of the core. This leaves each rod entirely free-from the cladding metal for a definite distance from the extreme end. I weld the tapered ends of the rods in endwise abutting relation, upsetting the weld sufficiently to make its minimum diameter greater than the original diameter of the core. I then subject the weldto hot I working and reduce its diameter substantially to that of the core. ;,1ayerto the coreleft exposed at the joint, to. a

I thenrestore the cladding II the joint.

thicknessequal to that of the layer on the rods intermediate their .ends. By uniting successive, composite, wire rods in this manner and. drawing them through the usual reducing dies, a continuous wire is produced in which the joints are practically indistinguishable from the remainder -of the wire from the standpoint of either physi- I cal strength or electrical conductivity and need not, therefore, becut out, thus making it possible to draw a. .uniform product of unlimited le'ngth. I

' A complete understanding of the invention may be obtained from the following detailed. descriptionand explanation which refer to the accompanyin'g drawings illustrating diagrammatically a' conventionalwire drawing line and the several steps of myimproved method. In thedrawmgs, I I Figure 1. is a diagrammaticelevation of a wire drawing line including apparatus for welding successive wire rods e'nd-to-end;

Figure 2' is a partial section showing a pair of -rod ends after being .machined and abutted preparatory to welding end-toI-end;

Figure 3 is an elevationshowingthe completed weldj" 1 I Figure 4 shows a weldafter a rough dressing operation; I

Figure 5 shows a weldafter it has been sub- -jected to hot working;

Figure-6 is anelevation showing the forged weld after: it has been finished to the desired finalldiameter; I

Figurefl illustrates therestoration of the cladding layer bybrazing metal over the portion of the core'left exposed at the joint; and

[Figure 8 illustrates theclad welded joint after .the':layer...of cladding metal applied theretohas been trimmed down tothe same outside diameter as the layer on the rods at a distance from ,=;Referring in detail to the drawings, composite ;wire composed of a core having a layer of cladding metal welded thereon is produced by drawing wire rods through a succession of dies. Figure .l illustrates the apparatus diagrammatically.

Coiled'wire rods III are placed on an uncoiler H and. drawnthrough reducing dies I2, I13 and -;by drawing blocks [5, l6 and I1. Apparatusfor carrying out the method of my invention may conveniently be located between the uncoilerll and the first reducing die [2 as indicated diagrammaticallyat l8. C'onsidering compositewire having a steel ,core and a copper cladding layerthereon, for the purpose of explanationit is desirable to produce such wire in unlimited lengths or, at least, to join successive wire rods end-to-end and thus avoid the necessity for threading each individually through the dies Almost any type of weld will suflice, for the latter purpose but the welded joint must be cut out of the finished'prodnot. This limits the amount of wire that can liminary dressing of the weld removes from the be drawn in a single length to that which be produced from a single wire rod. Longer lengths are frequently desirable iandavoidance of the necessity for cutting out the welded. joints weld any ruptures, cavities or accumulation of oxide Whether on the surface or below it, which might cause defects if not eliminated before drawing down the joint. '-In other words, the dressing j'lea'ves a clean surface at the Weld for subsequent would obviously improve the efficiency of opera- 7 tion. The method of my invention nowto be described in detail permits the both these objectives. v a

In a preferred practice, I start a wire rod through the dies and draw it into wire progressively until the trailing end of the coiled wire rod approaches the first die I2. I then stop the drawing blocks, place the next coil of wire rod on the uncoiler II and straighten the trailing end of the rod which has already. been drawn and. the leading end'of thesucceeding rod. I next removethe cladding layer from the adjacent ends and finish thelatter to .aisquare face. Specifically,.I1finishthe ends. of the wire rods to. be

joined on ataper asshown in Figure 2, to a minimum diameter less than that of the-core. In

Figure 2, It represents the trailing end of the .wire rod'whichhas beenadrawn .into. wire,. for the most part, and R the leading end of the next succeeding rod. Both the. rods comprise a central steel core 19. anda claddinglayer 2'0 welded thereon. The cladding layer. may be removed from the rod ends by any convenient machining operation, i.'e., turning-,cutting or grinding. The important consideration .is thatv the taper on which the ends are machined is such as to .leave a portion 2l at the end-:of-"each rod which is 'entirely freefrom the cladding metal. This result may be attained by-machining the extreme ends of the rodsto .adiameter somewhat less thanthe original diameter of .the .core [9. In the case of a rodhaving .a core.'.318" in diameter,.for example, it is sufficient .to .machine' the extreme ends of the rod starting at a distance of about 1"" from theJends to adiameterof. .25 at thetextreme ends. The regions 2| adjacent theends are thusleft entirely free-of; cladding metal for a distance of about :These dimensions, 'however, and those given below are illustrative only since the inventionis applicable to rods of .dif-

ferent sizes having different thicknessesof cladding thereon. Theiextremitles of .thez rodsv are preferably finished to give thema plane face normal to their axis before being. .machinedon 2a taper as just described. This facing andmachining may be effectedbyiany suitablemechanism incorporated inthe apparatus indicated diagrammatically at l8.

When the rod ends R and R. have-been preliminarily. machined as described above, "they are welded together by any suitable type-of welder,

e. g., a conventional electric butt'welder, which may be included inthe-apparatus I 8. Whatever the apparatus employed, the welding is accomipanied by a pushu-p jsuflicient to upset the weld asindicated at 22' in Figure 3. The upsetting should be continueduntil the minimum diameter of the core adjacent theweldis somewhat greater than the original diameter ofthe cores. In the case "of cores .3-18" in-diameter, the

'diameter'of the core adjacent the weld after upsetting. should be "about .33.

The maximum diameterm'aybe as great as 370".

accomplishmentof forging operation. The amount of reduction effected by the dressing is regulated to leave enough metal to produce a reduction of 40 to 50% in sec- I ing as by forging with a hammer or squeezing between suitable press jaws, thereby further reducing the Weld to a diameter of about .360 and the condition illustrated at 24 in Figure 5. This forging reduces the grain size from therelatively large magnitude resulting from the welding heat toa much smaller .size. This improvedmicrostructure .of'the .Weld causes therod to acquire a strength equal to that of the cores themselve "after suitable heattreatment.

After forging, the: weld should 'havea diameter greater than thatof the cores, i. e., .360," in the specific example given. After theforging of the weld .has been completed, .the joint is.fur.ther dressed downto substantially the diameter of the cores, 1. e., .318" :as indicated at 25 in Figure 6. The sectional area of .the steel at the joint. is thuszmade uniform 'withthe other portions of the rods.

After .finally dressing the weldedjoint, a layer of .cladding'metal i'sibrazed thereon and .united mode, as illustrated at 2''! .in Figure. 8. Since "fl tobewelded. By effecting this removal on a integrally'with the layers Men the -.ends vof the rods which have been welded together. For this purpose, I employ .a split graphite .mold provided with an induction. heating coil. Small pieces of copper deposited in. themold: are melted and fill the cavity in the "latter, thereby forming a sheath 26 around the .finished weld 25,

somewhat thicker than the cladding layer 20.

The excess :metal is'th'en removed from the sheathZfi surrounding theifinished joint 25 after which the lfil'llShEd joint is practically indistinguishable from the. remaining portions of..the

the sectional .area ofithesteel core at the joint .is substantially the samesas the original section of the 'coresand the sectionalarea of the cladding area .is restored to itsv original. value and since the grain size of the twelde'd portion has been refined Icy-forging, .the physical characteristics of the weld, such as strength, ductility, electrical conductivity-,etcare substantially the same asthose of other portions of the rods.

After the rodends havebeen united and linished --as described above, the drawing blocks are-'ag-ainstartedand re-duction'of the wire rod onthe uncoiler l lproceeds until its trailing (and approaches the die l2 whereupon the operations'described above are repeated.

' It will be apparent from the foregoing description and explanation that the invention provides a method of joining composite wire rods having numerous advantages over existing practice. In the first place, inclusion of the cladding metal in the core metal at the weld is prevented by completely removing the cladding layer from the cores adjacent" the ends taper, I insure that the extreme ends of the rods are entirely free from the cladding layer. At the same time, the welding and upsetting of the bared ends of the cores restores the section of core metal at the weld to the amount needed to give the resulting product as much strength at the Weld as in other portions. By forging the core metal upset during the welding, furthermore, I reduce the grain size thereof so that on proper heat treatment, the joint acquires all the original strength and other physical properties of the core. By replacing the cladding layer to precisely the right thickness, the conductivity of the Wire at the joints may be made the same as in other portions. Trimming off the excess cladding metal poured around the joint permits the joints to pass through the welding dies without imparting any sudden shock thereto. As a result of the invention, therefore, composite wire may be drawn continuously in as long lengths as may be desirable and it is not necessary to remove the Welded joints as they come through the final reducing die.

Although I have illustrated and described a preferred practice of the invention, it will be understood that changes in the procedure disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a method of uniting, end-to-end, metal rods composed of a core and a layer of cladding metal thereon, the steps including tapering the ends of the rods by the removal of metal therefrom to a minimum diameter at the extreme ends less than that of said cores, butt welding the cores, upsetting the weld to render the minimum diameter thereof greater than the diameter of saidcores, reducing the diameter of the upset weld substantially to the diameter of said cores, applying cladding metal over the joint to a thickness greater than that of said layer, and reducing the'external diameter of said cladding metal so applied substantially to the normal outside diameter of said layer.

2. In a method of uniting, end-to-end, substantially uniform metal rods composed of a ferrous core and a cladding layer of copper thereon, the steps including tapering the ends of the rods by the removal of metal therefrom to a minimum diameter at the extreme ends less than the diameter of the cores, pressure butt welding the ends of the cores together, upsetting the weld to make the minimum diameter of the weldgreater than that of the cores, reducing the weld substantially to the diameter of said cores,

and applying molten copper around the welded cores left exposed at the joint to Weld the said layers on said rods into a continuous cladding layer of uniform diameter.

In a method of uniting, end-to-end, metal rods composed of a core and a layer of cladding metal thereon, the steps including tapering the ends of the rods by the removal of metal therefrom to a minimum diameter at the extreme ends less than that of said cores, pressure welding the cores in abutting relationship, upsetting the Weld to render the minimum diameter thereof greater than the diameter of said cores, reducing the diameter of the upset weld by hot working and dressing substantially to the diame ter of said cores, and applying cladding metal over the joint to weld the layers of cladding metal on said rods into a continuous cladding layer of uniform diameter.

4. Ihe process of forming a continuous composite metal rod from two or more such metal rods each having a metal core and a covering of cladding metal surrounding said core, comprising, filleting the ends of the rods to be joined by the removal of metal therefrom to a minimum diameter at the extreme ends less than that of said cores, pressure Welding the cores at said respective ends in abutting relation to each other, upsetting said weld of said cores by axial pressure to make the minimum diameter thereof at least as great as the normal diameter of said cores, working said upset portion to restore it essentially to the normal diameter and strength of said cores, and covering said joint with molten cladding metal to form a continuous rod with a continuous layer of cladding metal of uniform diameter thereon.

JOSEPH G. AYERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 347,142 Thomson Aug. 10, 1886 396,011 Thomson Jan. 8, 1889 1,607,968 Spire Nov. 213, 1926 1,978,776 Williams Oct. 30, 1934 2,062,886 Jensen Dec. 1, 1936 2,078,546 Sebell Apr. 27, 1937 2,158,799 Larson May 16, 1939 2,177,868 Chapman Oct. 31, 1939 2,209,290 Watts July 213, 1940 2,268,617 Pierce Jan. 6, 1942 2,336,297 Rooke Dec, 7, 1943 2,356,854 Kirk Aug. 219, 1944 

1. IN A METHOD OF UNITING, END-TO-END, METAL RODS COMPOSED OF A CORE AND A LAYER OF CLADDING METAL THEREON, THE STEPS INCLUDING TAPERING THE ENDS OF THE RODS BY THE REMOVAL OF METAL THEREFROM TO A MINIMUM DIAMETER AT THE EXTREME ENDS LESS THAN THAT OF SAID CORES, BUT WELDING THE CORES, UPSETTING THE WELD TO RENDER THE MINIMUM DIAMETER THEREOF GREATER THAN THE DIAMETER OF SAID CORES, REDUCING THE DIAMETER OF THE UPSET WELD SUBSTANTIALLY TO THE DIAMETER OF SAID CORES, APPLYING CLADDING METAL OVER THE JOINT TO A THICKNESS GREATER THAN THAT OF SAID LAYER, AND REDUCING THE EXTERNAL DIAMETER OF SAID CLADDING METAL SO APPLIED SUBSTANTIALLY TO THE NORMAL OUTSIDE DIAMETER OF SAID LAYER. 